This invention relates to reusable and re-collapsible containers, and particularly to a one-piece container having a peripheral side wall which is arranged to include areas of differential wall thickness and diameter to thereby permit collapse of the container from an extended to a collapsed condition by reason of a telescoping relationship between the various portions of the peripheral side wall.
Collapsible containers, drinking cups and the like are, of course, well known. For example, in applicant's own prior U.S. Pat. No. 4,930,644, a collapsible, thin film plastic container is disclosed wherein a major portion of the container side wall has a reduced wall thickness to permit random collapse of the side wall. In U.S. Pat. No. 4,865,211, a plastic bottle having a uniform wall thickness throughout the side wall, is configured to permit collapsing of the container through telescoping movement of one portion of the side wall into another portion of the side wall.
In U.S. Pat. No. 4,875,576, a container is disclosed wherein an intermediate portion of the side wall incorporates a bellows-type arrangement for facilitating collapse and extension of the container. The patent also discloses the use of helical creases which spiral or angle between first and second portions of the container side wall to facilitate collapsing action of the creased portion of the side wall.
In U.S. Pat. No. 4,873,100, a bi-stable, expandable plastic bottle is disclosed which incorporates a bellows-type side wall for movement between collapsed and extended positions.
In U.S. Pat. No. 2,880,902, a collapsible, drinking cup (or camera bellows) is disclosed wherein the side wall is composed of alternating thick and thin portions.
The present invention incorporates a number of features not previously found in the prior art and which result in simple, easy-to-use, low cost containers which may be used and reused by the consumer as desired, and which may be stored in a collapsed condition, maximizing storage space, etc. At the same time, by significantly reducing the thickness of the container side wall in an intermediate portion thereof, source reductions in the amount of plastic required to manufacture the containers are realized.
More specifically, in the various exemplary embodiments disclosed herein, one-piece blow molded containers are each formed with a peripheral side wall divided into upper, intermediate and lower portions of substantially the same axial length, with the upper and lower portions having significantly greater wall thickness than the intermediate portion. For example, the intermediate portion may have a wall thickness of preferably between about 2 and about 12 mils which permits the intermediate portion to reverse fold as the upper and lower portions, which may each have a wall thickness of at least about 35 mils and preferably in the range of about 35-45 mils, are moved toward one another in the aforementioned telescoping relationship.
It is also a feature of the invention that the peripheral side wall of each container include surface configurations which facilitate the axial collapse of the container. In one embodiment, a radially outwardly flared portion may be provided at the lowermost edge of the upper side wall portion which serves as a guide surface as the intermediate portion and lower portion are axially collapsed and telescoped into the upper portion. In this same embodiment, the interface between the intermediate and lower portions may be indented to further facilitate the collapsing action.
Another feature of this first embodiment which facilitates the axial collapse of the container is the provision for a plurality of obliquely oriented grooves within the intermediate, thin side wall portion which, upon slight twisting action imparted to one or the other (or both) of the upper and lower side wall portions, causes the intermediate portion to immediately collapse and reverse fold upon itself as the upper and lower portions are pushed toward each other.
It is another feature of the invention to provide gripping means at either end of the container to assist the user to collapse, extend and re-collapse the container during its useful life. For example, where the discharge opening in the top wall of the container is provided with a conventional screw cap arrangement, a radially outward directed flange just below the threaded portion provides a convenient first gripping location. At the lower end of the container, an annular groove may be provided where the lower portion of the side wall joins with the bottom wall to provide a second convenient and easily accessible gripping location. In an alternative to the above described arrangement, a radially outwardly directed foot or flange may be provided in the lower side wall portion and which extends radially beyond all of the side wall portions, so that the flange also serves to support the upper portion of the side wall when the container is in the collapsed condition. As yet another alternative to the lower gripping arrangement, a pull tab or ring may be formed integral with the bottom wall, and the tab or ring may be folded over and releasably latched in a horizontal, out of the way position so as to not to interfere with the stability of the container.
In alternative embodiments of the invention, the upper and lower peripheral side wall portions may be provided to a greater or lesser extent with a plurality of annular reinforcing ribs which provide hoop strength to these relatively thicker portions of the side wall, and which therefore also especially facilitate the telescoping action of the container to the collapsed condition.
It will also be appreciated that in order to achieve the above described telescoping/collapsing action, the cross sectional areas of the upper, intermediate and lower portions are successively and progressively reduced (or increased) in one or the opposite direction so that an overall tapering effect is achieved. Within the individual portions, the side wall may also have a slight taper in the same direction.
Additional embodiments of the invention are disclosed which are particularly adapted for use as 2 1/2 gallon water (or other liquid) containers, and which are provided with a valve mechanism in the lower portion of the peripheral side wall. In these embodiments, an internal vacuum is created through the dispensing of the container contents which thereby causes the container side wall portions to collapse automatically by means of the above described telescoping action.
In another aspect of the invention, external holders are provided for optional use with the containers. These holders, which may also have insulating properties to retain heat or cold, are designed to support the container and to facilitate pouring of the contents from the container.
Accordingly, in its broader aspects, the present invention relates to a collapsible, extendable and recollapsible, plastic container comprising a bottom wall; a top wall; and a peripheral side wall extending between the bottom wall and the top wall, the side wall having at least three axially extending portions of substantially equal length, including an upper portion, an intermediate portion and a lower portion, wherein the intermediate portion has a wall thickness less than wall thicknesses of the upper and lower portions, and wherein cross-sectional areas of the side wall portions progressively vary so that the upper and lower portions may be telescoped one into the other with the intermediate portion reverse folded therebetween, and wherein a dispensing opening is provided in one of the top wall and peripheral side wall.
Additional objects and advantages of the invention will become apparent from the detailed description which follows.